Member asks: How long should I store digital images?

We’ve received a number of member questions regarding how long radiology departments are required to store images. Read on to learn what regulation exists, and what your peers are doing in practice.

Federal and state requirements for imaging storage

In the Code of Federal Regulations, 42 CFR 482.26(d), the condition for participation regarding radiologic services states that hospitals are required to retain imaging report copies and printouts, films, scans, and other radiologic services image records for five years.

Some states follow federal regulations, but many require that providers store images for several years longer, or have stricter standards for minors. You can find the regulatory rules in your state with this table, written by the American Healthcare Information Management Association.

Is digital storage different?

While there are federal regulations around film, legislation hasn’t caught up with technological advances, so in many cases, guidance around minification is going to be outdated. Obviously the closest corollary is going to be compression of digital images.

“The ACR and this technical standard make no general statement on the type or amount of compression that is appropriate...The type and amount of compression applied to different imaging studies transmitted and stored by the system should be initially selected and periodically reviewed by the responsible physician to ensure appropriate clinical image quality, always considering that it may be difficult to evaluate the impact on observer performance objectively and reliably.

If reversible or irreversible compression is used, only algorithms defined by the DICOM standard such as JPEG, JPEG-LS, JPEG-2000 or MPEG should be used…The DICOM standard does not recommend or approve any particular compression scheme for any particular modality, image type, or clinical application...”

But should we really purge?

On a more anecdotal level, we’ve heard from members that very few programs have actually “pulled the trigger” with purging digital images from PACS, and of those programs, very few have a formal policy in place to determine when images can be purged. Given that the price of storage media for PACS archives has been falling rapidly over the last decade, many institutions have chosen to store all digital images indefinitely in their archives.

However, it is fair to say that some smaller institutions are facing storage crises at the moment. Both rising digital imaging volumes, and the increasing size of digital images are straining some older archive architectures, and those stuck using only PACS vendor provided storage hardware are finding it difficult to take advantage of newer and cheaper off-the-shelf storage hardware.

Some of these institutions are taking the plunge and purging data that has exceeded state/federal retention periods. However, those who do not want to actually purge the images are looking to buy time using imaging compression.